python - 无法将函数输出分配给列

Question

我有一个名为“位置”的数据框，如下所示:

Home Number       Workplace Number      Year
A                 D                     1998
B                 H                     2001
C                 F                     2012
D                 O                     2005

我已经使用“家庭号码”创建了一个网络图。这里我想根据家庭网络计算家庭和工作场所之间的最小路径长度。对于给定的家庭和工作场所，我可以将它们插入以下函数:

def get_path_length(home_id, workplace_id):
    if home_id in nodes:
        try:
            path_length = nx.shortest_path(G, source = home_id, target = workplace_id)   
            print(path_length)
        except nx.NetworkXNoPath:
            path_length = -8888
    else:
        path_length = -9999
    return(path_length)

当我将相同的函数应用于数据帧中的每一行，然后将结果存储在名为“路径长度”的列中时，就会出现问题。我尝试了以下方法:

location_data = locations[['Home Number','Workplace Number']]

locations['Path Length'] = location_data.apply(get_path_length,axis=1)

但是我得到了一个错误:

TypeError: ("get_path_length() missing 1 required positional argument: 'Workplace Number'", 'occurred at index 0')

我还尝试迭代每一行:

for index, row in locations.iterrows():
    locations[index,'Path Length'] = get_judge_path(row['Home Number'],row['Workplace Number'])

但随后出现错误:

ValueError: Length of values does not match length of index

有人知道如何解决这个问题吗？

Answer 1

您可以在 lambda 函数中传递 2 列:

f = lambda x: get_path_length(x['Home Number'], x['Workplace Number'])
locations['Path Length'] = locations.apply(f, axis=1)